1. Field of the Invention
The present invention relates to methods and apparatus for providing privacy and authentication in a wireless network. More particularly, the present invention provides a system using both public key and shared key encryption techniques for communications between wireless mobile devices and a base station.
2. Art Background
The advent of portable personal computers and workstations has expanded the concept of networks to include mobile devices. These mobile devices may be moved between global networks as well as within local networks. For example, a user of a portable notebook computing device may physically carry his computer from Palo Alto, California to Bangkok, Thailand. If the computer must interact and communicate with other computers coupled to a network, issues of network security naturally arise. In particular, if the user's computer communicates over a wireless link, for example with a local base station or through a direct satellite link from Bangkok to the United States, wireless security, privacy and authentication becomes important. The wireless medium introduces new opportunities for allowing eavesdropping of wireless data communications. Anyone with the appropriate type of wireless receiver may eavesdrop, and this kind of eavesdropping is virtually undetectable. Furthermore, since the wireless medium cannot be contained by the usual physical constraints of walls and doors, active intrusions through the wireless medium are also easier to accomplish.
As will be described, the present invention provides a method and apparatus for preventing the opportunity for unauthorized access to the network, and a secure communication protocol that provides for both privacy of the wireless data communications, as well as authenticity of the communicating parties.